CO2加氢制烯烃取得新进展(Progress in research on CO2 hydrogenation to olefins)
Converting CO2 to olefins is an ideal route to achieve carbon neutrality. However, selective hydrogenation to light olefins, especially single-component olefin, while reducing CH4 formation remains a great challenge. Herein, we developed ZnZrOx/SSZ-13 tandem catalyst for the highly selective hydrogenation of CO2 to light olefins. This catalyst shows C2=-C4= and propylene selectivity up to 89.4% and 52%, respectively, while CH4 is suppressed down to 2%, and there is no obvious deactivation. It is demonstrated that the isolated moderate Brønsted acid sites (BAS) of SSZ-13 promotes the rapid conversion of intermediate species derived from ZnZrOx, thereby enhancing the kinetic coupling of the reactions and inhibit the formation of alkanes and improve the light olefins selectivity. Besides, the weaker BAS of SSZ-13 promote the conversion of intermediates into aromatics with 4-6 methyl groups, which is conducive to the aromatics cycle. Accordingly, more propene can be obtained by elevating the Si/Al ratio of SSZ-13. This provides an efficient strategy for CO2 hydrogenation to light olefins with high selectivity.
近日，我组在CO2加氢制低碳烯烃方面取得了新进展。团队发展了ZnZrOx/SSZ-13串联催化剂，实现了CO2到低碳烯烃的高选择性生成，其低碳烯烃选择性接近90%，其中丙烯选择性达到52%。
李灿院士团队长期致力于人工光合成相关研究，发展太阳能等可再生能源制备绿氢，进而将CO2加氢转化为甲醇（液态阳光）以及高附加值燃料或化学品，这是典型的人工光合成过程，也是实现碳中和目标的重要技术路径。团队先后发展了以ZnZrOx为代表的一系列金属氧化物固溶体催化剂（Sci Adv. 2017; ACS Catal. 2019; J Catal. 2021; J Catal. 2021; Chinese J. Catal. 2022），实现了CO2高选择性加氢制甲醇，并于2020年10月，完成了全球首套千吨级液态阳光工业中试示范，目前正在与中煤集团、华电集团等合作开展10万吨/年液态阳光工业化项目。以金属氧化物固溶体催化剂为基础，团队率先发展了以ZnZrO为基础的串联催化剂用于CO2加氢，实现了80%的低碳烯烃选择性和70%的芳烃选择性（ACS Catal. 2017，Joule 2018，Appl Catal A-Gen. 2023，Chem Comm. 2023）。
本工作发展了ZnZrOx/SSZ-13催化剂，进一步提高低碳烯烃选择性达90%，其中丙烯选择性为52%。in situ DRIFTS及动力学实验表明，该催化剂实现了CO2加氢与烯烃形成两个反应在热力学和动力学上的耦合，表明中间体的迁移拉动了反应正向进行，降低了反应的活化能。因此，在ZnZrOx/SSZ-13催化剂上获得低碳烯烃高选择性。
相关研究成果以“Hydrogenation of CO2 to Light Olefins over ZnZrOx/SSZ-13”为题，于近日以全文形式发表在《德国应用化学》(Angewandte Chemie International Edition)上。该工作的第一作者是我组博士研究生陈思宇。上述工作得到了国家自然科学基金委，“人工光合成”基础科学中心项目(FReCAP, 22088102)，中国科学院战略先导科技专项(XDA21090202)的支持。(文/图 陈思宇)
文章链接：https://onlinelibrary.wiley.com/doi/10.1002/anie.202316874
链接地址：
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https://www.science.org/doi/10.1126/sciadv.1701290
2. Jijie W. et al. High-Performance MaZrOx (Ma = Cd, Ga) Solid-Solution Catalysts for CO2 Hydrogenation to Methanol. ACS Catalysis, 2019:
https://pubs.acs.org/doi/10.1021/acscatal.9b03449
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https://www.sciencedirect.com/science/article/pii/S0021951721000853;
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https://www.sciencedirect.com/science/article/pii/S0021951721004024?via%3Dihub
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https://www.sciencedirect.com/science/article/pii/S1872206721639074?via%3Dihub
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https://pubs.acs.org/doi/10.1021/acscatal.7b03251
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https://www.sciencedirect.com/science/article/pii/S254243511830518X?via%3Dihub
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https://pubs.rsc.org/en/content/articlelanding/2023/CC/D3CC01259J
9. Hanwen H. et al. Synthesis of tetramethylbenzene from CO2 hydrogenation over ZnZrO/ZSM-11 tandem catalyst. Applied Catalysis A, General, 2023:
https://www.sciencedirect.com/science/article/pii/S0926860X23003903?via%3Dihub
